Our election system is a mess. Voters wait more than seven hours to vote in some places and minority voters wait twice as long on average as whites. In some states, voter ID laws are so tough that elderly nuns are turned away at the polls because they lack drivers’ licenses or other official ID.

In another era, the Supreme Court might have stepped up and done something to fix our democracy. But this Supreme Court left the voters standing in the sun for hours and the nuns to fend for themselves. Other than vindicating the right of corporations to spend unlimited amounts of money on elections in 2010’s Citizens United v. FEC, the court has not had a lot to say about how elections should be run.

Now, the Supreme Court appears to be poised to make a major change in American democracy by gutting the Voting Rights Act. The court will hear arguments Wednesday in Shelby County v. Holder, which challenges section 5 of the Act – a key provision that allows the Justice Department to block state election practices that make it difficult for minorities to vote.

It is hard to believe the court is really considering striking down section 5. The Voting Rights Act has been a revered part of American law since 1965, when Congress passed it to end the systematic disenfranchisement of blacks in the South. For decades, it enjoyed bipartisan support. The last two laws reauthorizing it were signed by Ronald Reagan and George W. Bush. The Supreme Court has upheld it four times.

Section 5 contains the Act’s famous “pre-clearance” requirement. Jurisdictions in all or part of 16 states – most, though not all, in the South – have to “pre-clear” changes in voting procedures with the federal government. The Justice Department must determine that the proposed changes will not deny or abridge the voting rights of minorities.

Section 5 protects voters – including, indirectly, white voters – from all sorts of schemes. If election officials try to change the location of a polling place at the last minute to confuse voters, the Justice Department can stop it. District lines that are drawn to stop minorities from being elected; ballots that are difficult to understand; last-minute changes in voter ID or voting hours – all of these can be challenged under the Voting Rights Act.

Despite its bipartisan support in Congress and the White House, conservatives on the Supreme Court have reservations about section 5. In a 2009 ruling, Chief Justice John Roberts warned that the “pre-clearance” requirement raises “serious constitutional questions.” The court dodged the question of whether section 5 is constitutional in 2009, but this week’s case is likely to squarely address that question.

Shelby County – the largely white Alabama county bringing this challenge – and other jurisdictions want to get the Justice Department out of their elections. As a constitutional matter, they are arguing that Congress did not have the power to pass Section 5. In recent years, the Supreme Court has held that for Congress to enact civil rights laws under the 14th Amendment there must be “congruence and proportionality” between the harm it is addressing and the methods it is using. The court has used this dubious rule to strike down congressional laws protecting Americans from a wide variety of harms, including age discrimination and gender-based violence.

This is the first problem with this challenge to the Voting Rights Act: It is another dangerous attempt to prevent Congress from doing its job. The Constitution gives Congress broad power to pass civil rights laws. But the court’s conservative justices refuse to recognize that. At his confirmation hearings, Chief Justice Roberts told the Senate that he saw his role as being an “umpire,” calling balls and strikes. If he and his fellow conservatives strike down Section 5, they would be taking Congress’s place in the batter’s box and swinging for the bleachers.

The second problem with this challenge is what it could mean for how elections work. If section 5 is struck down, it will free up majority-white legislatures to draw district lines making it difficult or impossible for minorities to elect representatives. And it would make it harder to challenge last-minute changes in polling places, intentionally confusing ballots, and a wide variety of other campaign dirty tricks that people in power often resort to when they want to win.

In its campaign finance rulings, the Supreme Court has made it far easier for corporations to influence elections with their money. It would be a terrible thing for democracy if the court used this case to make it harder for actual voters to influence elections with their ballots.